1. Field
The invention relates to a wireless communication apparatus.
2. Description of the Related Art
Recently, wireless LAN devices using a 2.4 GHz ISM (Industry-Science-Medical) band have been supplied. Using the same 2.4 GHz band, a wireless communication device that transmits and receives data by a weak radio wave, like a wireless tag or a wireless communication device that transmits and receives data by amplitude information as in ASK (Amplitude Shift Keying), is present. In these wireless communication devices (herein after, referred to as 2.4 GHz wireless communication devices) that transmit and receive data using the 2.4 GHz band, a transmission signal transmitted by a wireless LAN device becomes an interference signal. During the signal transmission of the wireless LAN device, the 2.4 GHz wireless communication device may not transmit and receive any signal.
To address this limitation, a method has been proposed in which the 2.4 GHz wireless communication device transmits a data signal after transmitting a NAV (Network Allocation Vector) frame signal before the data signal is transmitted (see JP-A-2008-153807). Since the wireless LAN device stops the signal transmission during a given time upon receipt of the NAV frame signal, the wireless LAN device does not become a source interfering with the 2.4 GHz wireless communication device.